Correlation between porosity level and elastic modulus in a foamed hiped Ti alloy

Nowadays, in the manufacturing of highly customized prosthetic implants, the need of devices with mechanical properties close to the human bone’s ones plays a key role. In the present work, Ti6Al4V-ELI porous structures obtained by a solid-state foaming process were studied from a microstructural and mechanical point of view, being the aim to control the stiffness of the prostheses in order to be as much as possible close to the human bone’s one, thus reducing the stress shielding effect. Samples with different levels of porosity (average diameter variable between a few microns and about 50 microns) were investigated by means of contact ultrasonic tests in order to evaluate changes in terms of elastic properties. Metallographic observations combined with contact ultrasonic tests revealed that a good correlation exists between the foamed structure (quantity and average size of the pores) and the stiffness.